We did Yellowstone & Cody on our 97 day trip from Virginia to Alaska and the Arctic Circle This year(2013). You might want to consider doing the lower loop of Yellowstone, camping inside if space is available. Leaving and heading to Cody for a couple of days and returning to do the upper loop of Yellowstone. Cody Has a great museum (we took 2 days just at the museum). Yellowstone has something new & interesting around every curve in the road. We found site inside Yellowstone Each time we entered the park.